Cancer remains one of the most deadly threats to human health. In the U.S., cancer affects nearly 1.3 million new patients each year, and is the second leading cause of death after heart disease, accounting for approximately 1 in 4 deaths. It is also predicted that cancer may surpass cardiovascular diseases as the number one cause of death within the next decade. Solid tumors are responsible for most of those deaths. Although there have been significant advances in the medical treatment of certain cancers, the overall 5-year survival rate for all cancers has improved only by about 10% in the past 20 years. Cancers, or malignant tumors, metastasize and grow rapidly in an uncontrolled manner, making timely detection and treatment extremely difficult.
In the U.S., the age-adjusted incidence of breast cancer increased ˜1% per year between 1940 and 1990 (27, 28) and 0.4%/year between 1987 and 2002 (29), due, in part to increased exposure to environmental carcinogens. Breast cancer is now the second most common cancer (after skin cancer) in women, with 225,000 new U.S. cases and 40,000 breast cancer-related deaths per year. It is estimated that 1 in 8 women born this year will be diagnosed with breast cancer in their lifetime (34). The total number of women diagnosed with breast cancer is likely to grow significantly over the next 20 years as the demographics of the population shift towards an older population (34).